The complete mitochondrial genome of Nadezhdiella cantori (Hope, 1843) (Coleoptera: Cerambycidae)

Abstract The complete mitochondrial genome of Nadezhdiella cantori (Hope, 1843) is 16,049 bp in length, containing 13 protein-coding genes (PCGs), 22 transfer RNA genes (tRNAs), two ribosomal RNA genes (rRNAs), and an A-T rich region (control region). The gene order is conserved and identical to most other previously sequenced Cerambycidae. Phylogenetic analysis showed that the newly sequenced N. cantori was in a well-supported clade tribe Cerambycini, subfamily Cerambycinae. These results support the currently accepted taxonomy and provide a better understanding of the phylogenetic analysis of the Cerambycidae.


Introduction
Family Cerambycidae, known as longhorn beetles or longicorn beetles, contains over 30,000 species worldwide. There are more than 12,000 species described in subfamily Cerambycinae, the second largest subfamily. The phylogenetic relationship of Cerambycinae remains unclear (Lee and Lee 2020). A recent study suggested that mitochondrial genomics are useful for revealing phylogenetic relationships (Nie et al. 2021). According to the data from GenBank, the complete mitogenomes of 27 species of Cerambycinae have been reported so far. Nadezhdiella cantori (Hope, 1843), belonging to subfamily Cerambycinae, is an important citrus pest that feeds on the trunks and main branches of citrus trees (Wang and Zeng 2004) and is widely distributed in China, Laos, Thailand, and Vietnam. However, the complete mitochondrial genome of N. cantori has not been reported. In the present study, the characterization of the mitogenome of N. cantori is reported.

Results
The complete mitogenome of N. cantori (GenBank accession number NC_061180) is 16,049 bp in length, containing the entire set of 37 genes usually present in most insect mtDNAs (13 protein-coding genes (PCGs), 22 transfer RNA genes, and two ribosomal RNAs), and a putative control region ( Figure  2). Fourteen genes were transcribed on the minority strand (N-strand), whereas the others were oriented on the majority strand (J-strand). The overall base composition of the N. cantori mitogenome was A (40.1%), T (31.9%), C (17.2%), and G (10.8%), with a high A þ T bias of 72.00%.
A total of 31 bp intergenic spacer were dispersed in six locations, ranging from 1 to 22 bp in length. The longest interval between trnS2 and nad1 was 22 bp. Gene overlaps were found at 14 gene junctions and involved a total of 47 bp, the longest 8 bp overlap located between trnY and cox1. The length of 22 tRNAs varied between 64 bp (trnT, trnH, trnF, trnE, trnR, and trnG) and 71 bp (trnK), comprising a total of 1456 bp. The length of rrnL is 1289 bp with an A þ T content of 76%, and rrnS is 804 bp with an A þ T content of 70.5%. The 1356 bp control region is located between rrnS and trnI and has a remarkably high A þ T content (81.8%).
We reconstructed the phylogenetic relationships of 28 Cerambycinae species based on 13 PCGs. The Bayesian tree (Figure 3) showed that Cerambycinae is monophyletic. Most tribes are monophyletic, whereas Hesperophanini and Callidiini are not. N. cantori formed a sister to Aeolesthes oenochrous with high value support.

Discussion and conclusions
This study determined the gene sequence of N. cantori and analyzed the main characteristics of its mitochondrial genome. The mitochondrial genome is conserved in terms of gene composition, location, and direction, which are the same as other previously sequenced mitochondrial genomes of Cerambycidae (Yang et al. 2019;Li et al. 2021).  Phylogenetic analysis showed that Cerambycinae is monophyletic. Hesperophanini and Callidiini are not, which is consistent with the previous studies (Lee and Lee 2020;Nie et al. 2021). In its present phylogenetic position, N. cantori is clustered within Cerambycini species, consistent with its classification based on morphological data. The mitogenome of N. cantori will help with molecular identification and population genetic studies of the species. It also provides a basis for establishing the phylogenetic relationships of Cerambycinae.

Ethics statement
This study did not need ethical approval or permission to collect the sample. The sequenced species is common in China and is not included in the 'List of Protected Animals in China'. All of the research meets ethical guidelines and adheres to the legal requirements of the country the study was conducted in.

Author contributions
L.Z. collected the specimen, conceptualized and designed the idea; T.H. analyzed and interpreted the data; T.H. was responsible for the drafting of the paper; L.Z. was responsible for the revising it and for the final approval; all authors agreed to be accountable for all aspects of the work.

Disclosure statement
The authors declare that there is no potential conflict of interest. Data availability statement The mitogenome sequence data that support the findings of this study are openly available in GenBank of NCBI at https://www.ncbi.nlm.nih. gov/ under the accession no. NC_061180. The associated BioProject, SRA, and Bio-Sample numbers are PRJNA835288, SRR19143081, and SAMN28100428, respectively.